1. Field of the Invention
The present invention relates to a same polarity induction generator capable of effectively producing electric power and of reducing the torque thereof.
2. Description of the Related Art
Generators are hitherto constructed to permit N and S poles thereof to be alternately operated, typically. This produces reactive magnetic force, resulting in an electromotive force including many higher harmonic components followed by much loss among other losses such as copper winding and iron loss, etc.
Japanese patent publication No. 62-45787 discloses, as illustrated in FIG. 6, of that publication, one type of such a same polarity induction generator. The generator comprises a stator composed of a plurality of magnetic cores disposed on one circumference and spaced in succession away at an equal mechanical angle (at a particular electrical angle of 180.degree.), a rotor composed of a plurality of ferrite permanent magnets disposed on one circumference at the same angle as that of the aforementioned magnetic poles in an interlacing relation with respect to the latter, the magnets having their same polarities respectively on the outer and inner circumferences of the rotor, and coil windings wound around the magnetic cores, where magnetic densities are increased and decreased owing to and in synchronism with the rotation of the rotor, so as to intersect magnetic fluxes from the rotor, whereby a magnetic path is formed utilizing the same polarity poles, permitting the generator to be operated only with the same polarities.
The prior generator however has some drawbacks in that the magnetic fluxes are weakened because the magnetic paths 32 and 33 have a considerable length and the structure is very complicated requiring a large space and making manufacture thereof difficult.
Japanese Patent Laid-Open Publication No. 62-160061 discloses further another type of such generators wherein there is provided a structure for producing magnetic repulsive force between a stator and a rotor to assure a generator of reduced holding torque without having a bad influence upon generating operation of the device.
However, the generator of the type described above also suffers from drawbacks in that it is difficult to realize effective power generation, it is large-sized, and not easily manufactured, because it is a rotating magnet type.